In the field of cryptography and data security, in addition to conventional ciphers it is known to protect (scramble) data (referred to here as a “message”) by applying the data and a “key” or “mask” to a logical function that is invertible and commutative such as, for example, an XOR (exclusive OR) operation. This yields a randomly scrambled (protected) version of the message. Unscrambling involves applying the same key and the scrambled message to the same operation, thereby recovering the original message. Such data is conventionally in digital (binary) form.
Such data protection is considered much weaker than encryption since the only security lies in the key itself (which may be used repeatedly), and so is normally not employed by itself.